Peristaltic Pump

ABSTRACT

A peristaltic pump for conveying fluids includes a stator and a rotor supported therein. A flexible hose is integrated in the stator and the rotor includes radially arranged conveying elements which squeeze the hose over a section containing the fluid. The squeezed fluid section moves progressively in the hose under the effect of a motor connected to the rotor. The conveying elements are designed as rotatably mounted rollers that include at least two rolling bearings, of which the outer rings are connected via a common outer sleeve and of which the inner rings are connected to the rotor. Under the effect of the motor, the rotor moves in the stator and the outer rings of the conveying elements roll on the inner surface of the stator.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a peristaltic pump for conveying fluids,comprising a stator and a rotor supported therein, wherein a flexiblehose is integrated in the stator and the rotor comprises radiallyarranged conveying elements which squeeze the hose over a sectioncontaining the fluid, and wherein the squeezed fluid section movesprogressively in the hose under the effect of a motor connected to therotor.

A peristaltic pump is a positive displacement pump in which the mediumto be conveyed is pushed through a hose by the external mechanicaldeformation thereof. German Patent Document DE 10 2008 002 761 A1discloses an example of such a pump. A drawback of these pumps the highfrictional forces occurring between the hose and the conveying elementswhen the hose is squeezed. As a result of these increased frictionalforces, both the transmission driving the rotor of the peristaltic pumpand the hose itself are subjected to heavy loading.

Exemplary embodiments of the present invention are directed to aperistaltic pump having a long service life, in which the transmissionand conveying medium hose are prevented from becoming damaged duringoperation.

The peristaltic pump according to the invention comprises a stator androtor supported therein, wherein a flexible hose is integrated in thestator, and the rotor comprises radially arranged conveying elementswhich squeeze the hose over a section containing the fluid, and whereinthe squeezed fluid section moves progressively in the hose under theeffect of a motor connected to the rotor. According to the invention,the conveying elements are designed as rotatably mounted rollers whichcomprise at least two rolling bearings, of which the outer rings areconnected via a common outer sleeve and of which the inner rings areconnected to the rotor, wherein, under the effect of the motor, therotor moves in the stator and the outer rings of the conveying elementsroll on the inner surface of the stator.

Rolling bearings, also known as ball bearings, are bearings in which twocomponents that are movable relative to one another, namely the “innerring” and the “outer ring”, are separated by rolling bodies. They areused to support radial and axial forces in axles and shafts and areintended to minimize the power loss and wear caused by friction. Rollingfriction primarily occurs between the three main components, the innerring, outer ring and rolling bodies. Since the rolling bodies in theinner and outer rings roll on hardened steel surfaces with optimizedlubrication, the rolling friction of these bearings is relatively low.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The invention will be explained in greater detail hereinafter withreference to figures, in which

FIG. 1 is a schematic view of a pump head of a peristaltic pumpaccording to the invention,

FIG. 2 is a view along the sectional line A-A in FIG. 1 of a conveyingmeans according to the invention.

DETAILED DESCRIPTION

FIG. 1 shows a peristaltic pump 1 for conveying fluids. The peristalticpump comprises a stator 4, in which a flexible hose 3 is integrated overa substantially circular path (approximately 360°). As is illustrated inFIG. 1 by the arrow, a rotor 5 is supported in the stator 4. The rotorhas radially arranged conveying elements 2 a, 2 b, 2 c. The conveyingelements 2 a, 2 b squeeze the hose 3 in the section 10. A motor, notillustrated in greater detail, cooperates with the rotor 5 and, inparticular, moves the squeezed fluid section 10 progressively in thehose 3 in accordance with the direction of the arrow. The fluid is thusconveyed in the section 10 from the inlet E of the peristaltic pump 1 tothe outlet A of the pump 1. Of course, conveyance may also occur in adirection opposite that of the arrow. In this case the peristaltic pump1 may be used both for pumping and for suction.

The hose 3 is fixed in a hose clamp 9 in the region of the inlet E andof the outlet A of the pump 1, wherein the hose clamp 9 is connected tothe stator 4.

The conveying hose 3 is surrounded and guided almost completely by thestator 4. A valve function of the pump 1 is thus achieved. If the rotor5 is idle, at least two conveying elements 2 press the hose 3 so thatthe path for the fluid is blocked.

FIG. 2 shows a sectional view along the sectional line A-A in FIG. 1 ofa conveying element 2 of the pump according to the invention. Theconveying element 2 comprises two rolling bearings 6 a, 6 b. Eachrolling bearing 6 a, 6 b consists of an inner ring 8 a and an outer ring7 a. The rolling bodies 11 are located between the inner ring 8 a andthe outer ring 7 a. The inner rings 8 a of the two rolling bearings 6 a,6 b are connected rigidly to one another and to the rotor 5. The outerrings 7 a of the two rolling bearings 6 a, 6 b are interconnected andform a type of outer sleeve 7 of the conveying element 2. There is noconnection between the rotor 5 and the outer sleeve 7. It is thusensured that the outer sleeve 7 is mounted rotatably about the axis D.

FIG. 2 also shows the stator 4 and the hose 3 squeezed between thestator 4 and the outer sleeve 7.

The bearings 6 a, 6 b are connected to a common outer sleeve 7, whichprevents tilting of the outer rings 7 a of the rolling bearings. Inaddition, the pump can be adapted to different hose thicknesses orpumping pressures by varying the thickness of the outer sleeve 7.Moreover, the outer sleeve 7 provides the hose 3 with a smooth outersurface. This increases the service life of the rolling bearings 6 a, 6b, of the hose 3 and of the transmission. During pumping or suctionoperation of the pump 1, each conveying element 2 a, 2 b, 2 c thus rollson the hose 3 with virtually no frictional forces.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1-3. (canceled)
 4. A peristaltic pump for conveying fluids, comprising:a stator with an integrated flexible hose; a rotor supported in thestator, wherein the rotor comprises radially arranged conveying elementsconfigured to squeeze the hose over a section containing the fluid, andwherein the squeezed fluid section moves progressively in the hose underthe effect of a motor connected to the rotor, wherein the conveyingelements are rotatably mounted rollers comprising at least two rollingbearings, of which outer rings are connected via a common outer sleeveand inner rings are connected to the rotor, and wherein, under theeffect of the motor, the rotor moves in the stator and the outer ringsof the conveying elements roll on the inner surface of the stator. 5.The peristaltic pump as claimed in claim 4, wherein the hose extendswithin the stator over a substantially circular path.
 6. The peristalticpump as claimed in claim 4, wherein the hose is arranged in a region ofan inlet to and of an outlet from the peristaltic pump with a commonhose clamp that is connected to the stator.